Unloading valve sub for well pipes



July 4, 1967 E. L. POTTS UNLOADING VALVE SUB FOR WELL PIPES Filed Jan. 4, 1965 A 7 TOR/V5) United States Patent 3,329,213 UNLOADING VALVE SUB FOR WELL PIPES Ernest L. Potts, Houston, Tex., assignor to. Brown Oil Tools, Inc., Houston, Tex., a corporation of Texas Filed Jan. 4, 1965, Ser.'N0. 422,888 9 Claims. (Cl. 166226) ABSTRACT OF THE DISCLOSURE with the sleeve valve, one of the packings being exposed to fluid when the valve is moved to a port-opening position, and a protective sleeve is mounted in the body to cover the exposed packing when the valve is so moved.

This invention relates to unloading valve subs for well pipes and more generally to sleeve-type valves.

Unloading valve subs are commonly installed in well pipe strings above a well packer, particularly when the packer is used in cementing, acidizing or treating operations. The valve is employed to effect equalization of tubing and annulus pressures in conjunction with these operations and to permit circulation of fluids between the tubing and casing annulus as may be required.

The primary object in all unloading valve subs is to provide a valve means for opening and closing-01f a port in the pipe string when required. The opening of such a port may be accomplished from the surface by manipulating the tubing string either by rotation or by picking up and slacking-off of the tubing, or by a combination of rotation and picking-up and slacking-off on the tubing. The device, in accordance with this invention, incorporates the latter combination through the use of a releasable connection means such as a J-connection between the relatively movable parts of the tool.

One common feature in all commercial designs of unloading valves is the employment of an arrangement which includes a port located between the annular seal packings and a tubular closure member axially movablethrough the packings between positions opening and closing the port. In such an arrangement, when the closure member is moved to the port-opening position at least one set of the seal packings is necessarily exposed to the flow of fluid either into or out of the tubing string. Where a high pressure differential exists between the interior and the exterior of the tubing such fluid flow will necessarily be of high velocity, which will frequently be extremely damaging to the exposed seal packing, with the result that the valve may become ineffective after brief usage.

It is, therefore, a primary object of this invention to provide an improve-d form of unloading valve sub which will overcome the deficiencies of existing designs by providing means which will be automatically actuated by the opening movement of the valve closure to cover the otherwise exposed seal packing with a protector sleev'e.

An important object is the provision of a spring-actuated sleeve disposed in the bore of the tool to be automatically urged to a packing-covering position upon movement of the port closure element to a port-opening position.

Other and more specific objects and advantages of this invention will become evident from the following detailed description when read in conjunction with the accompanying drawing which illustrates one useful embodiment in accordance with this invention.

3,329,213 Patented July 4, 1967 In the drawing:

FIG. 1 is an elevational view, partly in section, of an unloading valve sub showing the parts thereof in the portopening position, and the related positions of the packingprotection elements;

FIG. 2 is a view similar to FIG. 1, showing the parts thereof in the port-closing position:

FIG. 3 is a cross-sectional view taken along line 3-3 on FIG. 1; and

FIG. 4 is a perspective, fragmentary view of the outer body member of the sub, showing the manner in which this member may be fabricated to form a J-slot within the bore thereof.

Referring to the drawing, the unloading sub, in accordance with this invention, is designated. generally by the numeral 10 and is adapted for connection between adjacent sections of a tubing string T. The unloading valve sub comprises a tubular inner mandrel 12 telescopically and concentrically extending into the bore of a tubular outer body 14. The upper end of mandrel 12 is provided with a threaded pin 15 for connection to a collar 16 by which the tool may be attached to the: upper section of pipe T. The lower end of outer body 14 is provided with an internally threaded socket 17 for receiving the pin portion 18 of an adapter 19 by which body 14 may be connected to the sub-adjacent section of tubing string T. Body 14 is counterbored from its upper end to form an upper stufiing box 20 terminating in an upwardly facing internal shoulder 21 to receive an upper seal packing 22 held between a pair of gland rings 23. The upper end of body 14 is provided with an internally threaded socket 24 adapted to receive a tubular bushing 25 which is adapted to slidably receive mandrel 12 and to compress upper packing 22 against shoulder 21. A seal packing 26, such as an O-ring seal, is provided between bushing 25 and the exterior of mandrel 12. Body 14 is also counterbored from its lower end to provide a lower stufling box 27 defined at its upper end by a downwardly facing shoulder 28 against which is seated a lower annular seal packing 29 held between gland rings 3030. Lower packing 29 is held against shoulder 28 by means of a spacer ring 31 which is disposed against the wall of body 14 and in compression against the seal packing by the inner end face 32 of adapter pin 18. A protector sleeve 33 is mounted concentrically in the bore of lower packing 29 to have a close sliding fit therewith, and is provided at its lower end with a radially outwardly extending flange 34 slidable over the inner face of spacer 31 and adapted to abut lower gland ring 30 which forms a stop member to limit its upward movement. Sleeve 33 is biased upwardly to the packing-enclosing position, shown in FIG. 1, by means of a coil compression spring 35 having one end seated on shoulder 32 and the other bearing against flange 34 of the protector sleeve. Body 14 has a plurality of radial openings 36 extending through the wall thereof and located between packings 22 and 29 for communicating the interior of the body with the exterior thereof.

Mandrel 12 has an external diameter such as to slidably and sealingly engage upper seal packing 22, and at its inner end has a tubular extension 12a adapted to similarly sealingly engage lower seal packing 29 when the mandrel is moved inwardly to the port-closing position shown in FIG. 2. The lower end of extension 1211 is arranged to abut the upper end of protector sleeve 33 as the mandrel is moved inwardly to the port-closing position, so that when fully inserted the mandrel will push sleeve 33 downwardly away from its position opposite packing 29 and compress spring 35, as seen in FIG. 2, the lower end of mandrel extension 12a serving to hold sleeeve 33 in the retracted position, shown in FIG. 2, so long as the mandrel is in the port-closing position. When the mandrel is retracted to the port-opening position, sleeve 33 will be advanced automatically to the packing-covering position by the action of spring 35.

A latch means of suitable form is provided between body 14 and mandrel to releasably secure the latter initially in its port-opening position. A preferred form of such latch means is a J-type connection wherein the interior of body 14 is provided with a pair of inverted J-slots, each comprising an elongate vertical leg 40, a horizontal leg 41, and a short vertical leg 42. Mandrel 12 carries a pair of radially extending J-lugs 43 cooperating with the respective J-slots, for connecting and disconnecting mandrel 12 from body 14 in operation of the device, as will appear subsequently. Mandrel 12 is also provided with an external shoulder 44 dimensioned to be slidably received in the bore of body 14 and positioned at a point which will be below upper packing 22 when the mandrel is in the fully retracted position. Shoulder 44 will serve to prevent the mandrel being pulled out of body 14 by engagement with the upper packing assembly which is held in place by bushing 25. A seal ring, such as an O- ring 45, is mounted in the periphery of shoulder 44 to seal with the bore wall of body 14. A vent port 46 is provided through the wall of mandrel 12 above shoulder 44 to prevent trapping of any pressure in the annular space between the mandrel and the body between packing 22 and seal ring 45 during relative movement between the mandrel and the body.

FIG. 4 is provided to illustrate one way in which the internal .T-slot may be fabricated in body 14. This may be done by milling a J-slot of the desired configuration through the wall of body 14 and then providing a fillet or cover 50 therefor of corresponding configuration but of thinner wall section than that of body 14. Fillet 50 is then inserted in the J-slot opening and welded therein with its exterior flush with the exterior of the body, with the resultant formation in the interior wall of the body of an inverted J-slot of the desired configuration, into which J-lugs 43 will extend.

In operation, it will be evident that with the valve sub mounted in a pipe string it will normally be run in a well in the open position illustrated in FIG. 1, wherein protection sleeve 33 will be in its advanced position covering lower packing 29 and protecting it against any fluid flowing through the valve. When it is desired to close the valve, the tubing string will be picked up slightly to move I-lugs 43 out of the short legs 42 of the J -slots and then a slight rotation to the right will move the I-lugs into alignment with longer legs 40, after which the pipe string may be lowered moving mandrel extension 12a into the bore of packer 29, at the same time engaging the protector sleeve and pushing it downwardly to the position shown in FIG. 2, at which position mandrel extension 12a will be in sealing engagement with packing 29, thereby closing ports 36.

It will be evident, therefore, that in all positions of the mandrel, that is, whether or not the mandrel is in the portopening or port-closing position, lower packing 29 will always be protected against the erosive or velocity effects of fluid flow, irrespective of the extent of pressure differentials which may exist against the tubing string and the annulus. Since upper packing 22 will, at all times, be in sealing engagement with mandrel 12, this packing will also, of course, be protected against the eifects of fluid flow through the valve.

It will be understood that various alterations and changes may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

1. A sleeve-type valve including a tubular outer body having port means through the wall thereof, a tubular closure member axially movable in the bore of said body between positions opening and closing said port means,

said closure member having an outer end projecting exteriorly of said body, longitudinally spaced annular seal packings positioned in the bore of said body on opposite sides of said port means for sealing engagement with said closure member, seal means mounted on said closure member for slidable sealing engagement with the bore wall of said body between said annular packings, vent passages through the wall of the closure member between said seal means and the outer one of said packings, one of said packings being exposed to fluid flow when said closure member is moved from the port-closing position to the port-opening position, a protection sleeve slidably disposed in the bore of said body for axial movement between an advanced position covering said one of said packings and a retracted position exposing the same to fluid flow through the body, means biasing said sleeve to said advanced position, said sleeve being movable to said retracted position by engagement by said closure member as the latter is moved from the port-opening to the port-closing position, and means carried by the outer ends of the closure member and said body for connecting the same to adjacent sections of a pipe string.

2. In a sleeve-type valve according to claim 1 wherein said biasing means comprises a coil spring mounted in compression between said sleeve and said body.

3. In a sleeve-type valve according to claim 1, latch means cooperably arranged between the body and the closure member for releasably securing said closure member initially in said port-opening position and releasable by relative movement between the closure member and the body.

4. In a sleeve-type valve according to claim 3 wherein said latch means is of the J-connection type.

5. An unloading valve sub for well pipe strings, comprising a tubular outer body having port means through the wall thereof intermediate its ends, longitudinally spaced annular packings positioned in the bore of the body in opposite sides of said port means, a tubular mandrel slidable axially in the bore of said body through said packings between an upper port-opening position having sealing engagement with the upper one of said packings and a lower port-closing position having sealing engagement with both said packings, said mandrel having an outer end projecting from the upper end of said body, seal means mounted on said mandrel for slidable sealing engagement with the bore wall of said body between said annular packings, vent passages through the wall of said mandrel between said seal means and said upper one of said packings, a protection sleeve slidably disposed in the bore of said body for axial movement between an advanced position covering the lower one of said packings and a retracted position exposing said packing to fluid flow through the body, means biasing said sleeve to said advanced position, said sleeve being disposed for engagement by the inner end of said mandrel as the latter is moved to the port-closing position to urge said sleeve to said retracted position, latch means cooperably arranged between the body and mandrel for releasably securing said mandrel initially in said port-opening position and releasable by relative movement between said mandrel and body, and means carried by the outer ends of the mandrel and body for connecting the same to adjacent sections of a pipe string.

6. An unloading valve sub for well pipe strings according to claim 5 wherein said biasing means comprises a coil spring mounted in compression between said sleeve and said body.

7. An unloading valve sub for well pipe strings according to claim 5, wherein said latch means comprises a ]-type connection.

8. An unloading valve sub according to claim 5 having stop means in the body cooperating with said sleeve to limit the extent of its movement to said advanced position.

9. An unloading valve sub according to claim 8 wherein said stop means comprises an abutment in said body, and a 5 6 flange on the sleeve member engageable with said abut- 3,083,770 4/1963 Villalon 166-237 X ment when said sleeve attains said advanced position. 3,094,307 6/1963 Alley 166-224 X 3,151,681 10/1964 Cochran 166-224 g gi gg gf 5 CHARLES E. OCONNELL, Primary Examiner. 2,874,927 2/1959 Conrad 166-226 X JACOB NACKENOFF Examme" 3,071 193 1 19 3 Raulins 15 22 N. C. BYERS, Assistant xaminer. 

5. AN UNLOADING VALVE SUB FOR WELL PIPE STRINGS, COMPRISING A TUBULAR OUTER BODY HAVING PORT MEANS THROUGH THE WALL THEREOF INTERMEDIATE ITS ENDS, LONGITUDINALLY SPACED ANNULAR PACKINGS POSITIONED IN THE BORE OF THE BODY IN OPPOSITE SIDES OF SAID PORT MEANS, A TUBULAR MANDREL SLIDABLE AXIALLY IN THE BORE OF SAID BODY THROUGH SAID PACKINGS BETWEEN AN UPPER PORT-OPENING POSITION HAVING SEALING ENGAGEMENT WITH THE UPPER ONE OF SAID PACKINGS AND A LOWER PORT-CLOSING POSITION HAVING SEALING ENGAGEMENT WITH BOTH SAID PACKINGS, SAID MANDREL HAVING AN OUTER END PROJECTING FROM THE UPPER END OF SAID BODY, SEAL MEANS MOUNTED ON SAID MANDREL FOR SLIDABLE SEALING ENGAGEMENT WITH THE BORE WALL OF SAID BODY BETWEEN SAID ANNULAR PACKINGS, VENT PASSAGES THROUGH THE WALL OF SAID MANDREL BETWEEN SAID SEAL MEANS AND SAID UPPER ONE OF SAID PACKINGS, A PROTECTION SLEEVE SLIDABY DISPOSED IN THE BORE OF SAID BODY FOR AXIS MOVEMENT BETWEEN AN ADVANCED POSITION COVERING THE LOWER ONE OF SAID PACKINGS AND A RETRACTED POSITON EXPOSING SAID PACKING TO FLUID FLOW THROUGH THE BODY, MEANS BIASING SAID SLEEVE TO SAID ADVANCED POSITION, SAID SLEEVE BEING DISPOSED FOR ENGAGEMENT BY THE INNER END OF SAID MANDREL AS THE LATTER IS MOVED TO THE PORT-CLOSING POSITION TO URGE SAID SLEEVE TO SAID RETRACTED POSITION, LATCH MEANS COOPERABLY ARRANGED BETWEEN THE BODY AND MANDREL FOR RELEASABLY SECURING SAID MANDREL INITIALLY IN SAID PORT-OPENING POSITION AND RELEASABLE BY RELATIVE MOVEMENT BETWEEN SAID MANDREL AND BODY, AND MEANS CARRIED BY THE OUTER ENDS OF THE MANDREL AND BODY FOR CONNECTING THE SAME TO ADJACENT SECTIONS OF A PIPE STRING. 